Shabtai Y, Gutnick D L
J Bacteriol. 1985 Mar;161(3):1176-81. doi: 10.1128/jb.161.3.1176-1181.1985.
An esterase activity has been found, both in the cell-free growth medium and on the cell surface of the hydrocarbon-degrading Acinetobacter calcoaceticus RAG-1. The enzyme catalyzed the hydrolysis of acetyl and other acyl groups from triglycerides and aryl and alkyl esters. Emulsan, the extracellular heteropolysaccharide bioemulsifier produced by strain RAG-1, was also a substrate for the enzyme. Gel filtration showed that the cell-free enzyme was released from the cell surface either emulsan free or associated with the bioemulsifier. The partially purified enzyme was found to interact specifically with the esterified fully active emulsan, but not with the deesterified polymer. A role for esterase in emulsan release from the cell surface was indicated when the enzyme was preferentially depleted from the cell surface under conditions in which emulsan was not released. Such cells lost the capacity to release the biopolymer.
在无细胞生长培养基和降解烃类的醋酸钙不动杆菌RAG-1的细胞表面均发现了酯酶活性。该酶催化甘油三酯以及芳基和烷基酯上的乙酰基和其他酰基的水解。乳化素是菌株RAG-1产生的细胞外杂多糖生物乳化剂，也是该酶的底物。凝胶过滤显示，无细胞酶从细胞表面释放时，要么不含乳化素，要么与生物乳化剂结合。发现部分纯化的酶与酯化的完全活性乳化素特异性相互作用，但与脱酯聚合物不相互作用。当在不释放乳化素的条件下，该酶优先从细胞表面耗尽时，表明酯酶在乳化素从细胞表面释放中起作用。这样的细胞失去了释放生物聚合物的能力。
